Questions arise after five airline near-collisions in a month

(CNN) – The National Transportation Safety Board says two planes came within a quarter of a mile of each other, flying rapidly at the same altitude, 1400 feet. Just seconds away from a fiery crash in the sky.

The cargo plane had just taken off on a collision course with the Alaska Airlines 737 attempting to land at Ted Stevens Airport in Anchorage. On board: 150 passengers and crew arriving from portland.

Shortly after 3:00 in the afternoon, alarms began blaring in the cockpit, an air traffic collision avoidance system on the jet alerting the crew to “traffic”, that another plane was nearby. Both were over Fire Island Alaska, just seven miles from the airport. Another deadly mid-air crash averted.

Marty Lauth, an associate professor at Embry-Riddle Aeronautical University told CNN “Usually when you get a TCAS, the collision avoidance alert. The pilot that gets this reading, most of the time they might have 15 seconds, 20 seconds.”

Tuesday’s incident is the latest in a series of disturbing near collisions in the last few weeks.

On April 24th, in Newark, a plane landing at the airport narrowly missed a plane taking off.

On April 25th, in the skies near Hawaii, collision avoidance alerts sounded in the cockpits of two planes as they approached each other.

Just this month, on May 10th at JFK Airport in New York, a passenger jet aborting a landing crossed too close to a plane taking off. The day before that, at Houston’s Bush Intercontinental Airport, a passenger plane taking off veered into the space of another aircraft that had just departed.

So why does this keep happening? Lauth, also a former air traffic controller, says the pressure is on to keep the planes flying and landing on time.

“The controller’s job is to keep these airplanes safely apart but without undue amount of separation between them. Because now all of a sudden airplanes start backing up and you have a lot of delays and so forth.”

The FAA says it is making changes to prevent this from happening in the future. For example, it says it recently changed rules for takeoffs and landings at Newark Airport.